Comparison of Surface Flows Derived from Different Resolution- DEM

Abstract

This paper presents the comparison of two digital elevation model (Dem) at different spatial resolution in Scania (Sweden). Dem as being digital representation of landscape topography consists of elevation values in an array; landscape features such as slope, aspect, drainage areas and channel network can be rapidly extracted using specialized numerical algorithms.Two elevation datasets have been used in this study: Shuttle Radar Topography Mission (SRTM) 90m resolution and GSD-Höjddata 50 m spatial resolution. The Study area is Skåne County also known as Scania County in English. It is the southernmost administrative county, of Sweden with an area of 11300 km2 (55°59′43″N 13°26′30″E). Arcgis software was used in this paper for analysis. The method has four subdivisions: data harmonization, investigating and filling sinks, modelling the surface flows and comparing the surface flows with a settled evaluation test. First, flow direction was extracted from DEM (D8 method) and sink areas were inspected and filled, and then flow accumulation and stream network were produced. Finally, streams were derived from both DEMs and compared with river vector data (reality). The result shows that the streams derived from GSD-Höjddata 50m resolution fits better to river data (reality) in comparison with streams extracted from resampled SRTM 90m resolution DEM